I got the SNES to do a super saw lead by making a BRR sample that is 8192 samples long, with each saw tooth oscillator being 253x to 259x the frequency of the loop.
Each BRR block uses filter 1, so that each wave oscillation only requires an "impulse" sample, and then a bunch of zeros, so making a super saw lead takes up less computation and also less noisy.
I tried making super saw BRR samples using samplers, but they never came out good. There was never any good looping points, and cross fading just makes it sound hollow. Because of the high frequency content, a super saw comes out quite noisy and filtered with typical BRR converters. So I decided to have the SNES's own 65816 make the BRR samples itself.
Plus the fact that doing it this way feels more "video gamey" and "chip tuney" then using a preprocessed sample that's been to hell and back.
I would post the .sfc file, but there isn't a button to do this on here.